New Compound Operators in GCBASIC: XOR= and OR=

[Anobium]

New Compound Operators in GCBASIC: XOR= and OR=

Hello GCBASIC community!

I am excited to announce that the latest compiler update now supports two new compound operators: XOR= and OR=. These join our existing compound operators (++, --, +=, -=) to provide more efficient bit manipulation capabilities.

New Operators and Their Equivalents

XOR= Operator

The new compound XOR operator simplifies your code. These two code blocks do exactly the same thing:

; Using new XOR= operator
myVar XOR= 0b00001111

; Equivalent traditional code
myVar = myVar XOR 0b00001111

Here's a real-world example showing both forms:

; Toggle an LED using XOR=
PORTB.0 XOR= 1    'Toggles bit 0 of PORTB

; Same operation written longhand
PORTB.0 = PORTB.0 XOR 1

OR= Operator

portStatus OR= 0b10000000   'Sets bit 7 while preserving other bits
flags OR= STATUS           'Combines status bits with existing flags

Practical Applications

XOR= Use Cases:

1. Toggle bits without affecting others - perfect for flipping specific LED states or inverting signal lines
2. Implement simple encryption - XOR with a key pattern for basic data scrambling
3. Swap values without temporary storage:

; Using XOR=
a XOR= b
b XOR= a
a XOR= b    'Values are now swapped!

; Equivalent code without XOR=
a = a XOR b
b = b XOR a
a = a XOR b

OR= Use Cases:

1. Set specific bits while preserving others - ideal for configuring port settings
2. Combine status flags from different operations
3. Enable features without disrupting existing settings

Example: Shift Register Control

Here's how these operators simplify shift register handling:

#define LATCH_PIN PORTC.0
#define DATA_PIN  PORTC.1
#define CLOCK_PIN PORTC.2

Sub UpdateDisplay(in displayPattern as Byte)
    ; Clear latch
    PORTC = PORTC AND NOT (1 << LATCH_PIN)

    ; Shift out 8 bits
     Dim bitcount as Byte
    For bitCount = 0 to 7
        ; Clear data pin
        PORTC = PORTC AND NOT (1 << DATA_PIN)

        ; Set data bit if needed
        If displayPattern.7 Then
            PORTC OR= (1 << DATA_PIN)  'Set only DATA_PIN
        End If

        ; Toggle clock using XOR=
        PORTC XOR= (1 << CLOCK_PIN)    'Toggle CLOCK_PIN

        ; Same toggle without XOR= would be:
        'PORTC = PORTC XOR (1 << CLOCK_PIN)

        displayPattern = displayPattern << 1
    Next

    ; Set latch to update display
    PORTC OR= (1 << LATCH_PIN)
End Sub

Bit Manipulation Examples

Here's a practical example showing how XOR= can simplify LED patterns:

; Flash alternate LEDs on PORTB
Sub FlashLEDs
    ; Toggle bits 0,2,4,6
    PORTB XOR= 0b01010101

    ; Equivalent without XOR=
    'PORTB = PORTB XOR 0b01010101

    ; Toggle bits 1,3,5,7 on next pass
    PORTB XOR= 0b10101010

    ; Equivalent without XOR=
    'PORTB = PORTB XOR 0b10101010
End Sub

Compatibility

These new operators are available in the latest compiler version. All existing code using the traditional compound operators (++, --, +=, -=) continues to work as before.

Give these new operators a try and let me know how they improve your code! As always, I appreciate your feedback and suggestions for future enhancements.

Enjoy

Evan

[stan cartwright]

remember ssd1309 oscilloscope xor mode to erase graphics by redrawing them?

[Anobium]

Yes, I still use it! And, the sprite demo!